This invention relates to systems for testing electronic circuits by applying and/or measuring electrical signals and, more particularly, to electronic circuit test systems for applying electrical signals to a packaged device or integrated circuit, or a device or integrated circuit chip on wafer, and measuring the response of the device or integrated circuit to the applied electrical signals. Specifically, one embodiment of the invention provides a blind mate connector for effecting an electrical connection(s) in an electronic circuit tester between a test head and a calibration board for the tester or, alternatively, a fixture board that interfaces with the device or integrated circuit being tested. The blind mate connector in accordance with one embodiment of the invention is particularly adaptable to a high-frequency electronic circuit tester for effecting connections between standard coaxial connectors of the test head, such as SMA or 3.5 millimeter connectors, and the calibration board or fixture board for increasing repeatability of connections, as well as for facilitating the setup and calibration of, and measurements with, the tester for testing high-frequency devices and integrated circuits, thereby improving reliability and enhancing overall throughput.
Programmable electronic circuit testers are typically used during the manufacture of electronic devices and integrated circuits to test the performance of the device or integrated circuit being manufactured. Tests are conducted to assure that the device or integrated circuit satisfies associated design performance specifications. In order to test the device or integrated circuit, the electronic circuit tester is programmed to inject an electrical signal or suite of electrical signals into the device or integrated circuit under test and to measure the response(s). The electronic circuit tester cannot only be used to test finished packaged devices and integrated circuits, but is also frequently used to perform tests at various stages of manufacture of the device or integrated circuit between initial wafer processing and final packaging.
A conventional programmable electronic circuit tester, generally indicated by the numeral 10, is shown in FIG. 1. The electronic circuit tester 10 comprises a test head 12 electrically connected by cables routed through a conduit 14 to a rack(s) 16 of electronic test and measurement instruments, such as ac and dc electrical signal generators for applying electrical signals to a device or integrated circuit interfaced to the test head, and signal analyzers, for example, an oscilloscope and a network analyzer, for measuring the response(s) to those applied electrical signals. As shown in FIG. 1, the test head 12 interfaces to a device or integrated circuit through a load board 18 connected to the cables in the conduit 14 and fixture board 20 in turn connected to the load board. Alternatively, prior to installation of the fixture board 20, a calibration board can be connected to the test head 12 for calibrating the test head. The configuration of the load board 18 depends on the type of device or integrated circuit being tested, such as an analog or digital electronic circuit, while the configuration of the fixture board 20 is typically specific to the family of device or integrated circuit being tested.
As shown in FIG. 1, the test head 12 is mounted on a dolly 22. Since the electronic circuit tester 10 can be employed to test both packaged devices and integrated circuits, as well as device or integrated circuit chips on wafer, the test head 12 is preferably mounted by pivotable connections 24 to the dolly 22. The pivotable connections 24 enable the test head 12 to be positioned in an approximately upward facing horizontal position so that the appropriate load board 18 and calibration or fixture board 20 can be mounted on the test head of the electronic circuit tester 10 by an operator. The test head 12 can also be pivoted to a vertical position so that the fixture board 20 can interface with a material handler, for example, to test packaged devices or integrated circuits. Finally, the test head 12 can be pivoted to a downward facing horizontal position so that the fixture board 20 can interface with a wafer to test device or integrated circuit chips on the wafer.
The connectors through which the test head 12 is electrically connected to the calibration or fixture board 20 are subjected to many connections and disconnections during calibration and actual testing with the electronic circuit tester 10. However, the useful life of the electronic circuit tester 10 has heretofore far exceeded the useful life of the connectors in the test head 12 and calibration or fixture board 20. Also, the repeatability of the connections that are effected decreases over time as the connectors degrade due to wear of the connectors. Moreover, high-frequency coaxial connectors are relatively fragile, and the center conductor of such a connector can be damaged if caution is not exercised by the operator when connections are effected.
It would therefore be desirable to provide a connector structure to repeatably connect the test head 12 to the calibration or fixture board 20 over a longer period of the useful life of the electronic circuit tester 10 during setup and calibration and actual testing. Additionally, it is desirable to provide a relatively rugged connector structure whereby the connector is less susceptible to wear and damage when connection is effected. Such a structure would facilitate the use of the electronic circuit tester 10 to perform setup and calibration, as well as the measurement process.